Question

1) How can you experimentally find the center of mass of a long rod, such as a meter stick?

Answer 1

If the object is just a long rod, then the center of mass can be found by balancing the rod on some kind of a pivot or fulcrum, such that the rod looks like a see-saw.

The mass of the rod can be assumed to act at the center of mass. So, only when the fulcrum is located exactly at the center of mass will the rod stay balanced perfectly horizontally. If the center of mass is to the left of the fulcrum, the rod will tilt to the left, and if the center of mass is to the right of the fulcrum, the rod will tilt to the right.

So, find that point, where the fulcrum should be placed to balance your rod, and you will have found the center of mass.